diff --git a/inc/YeltsinDB/constants.h b/inc/YeltsinDB/constants.h
index 5344e63..939e568 100644
--- a/inc/YeltsinDB/constants.h
+++ b/inc/YeltsinDB/constants.h
@@ -10,7 +10,7 @@
  */
 
 #define YDB_TABLE_FILE_SIGN "TBL!"
-#define YDB_TABLE_FILE_SIGN_SIZE (sizeof(YDB_TABLE_FILE_SIGN))
+#define YDB_TABLE_FILE_SIGN_SIZE (sizeof(YDB_TABLE_FILE_SIGN)-1)
 #define YDB_TABLE_FILE_VER_MAJOR_SIZE (1)
 #define YDB_TABLE_FILE_VER_MINOR_SIZE (1)
 #define YDB_TABLE_FILE_DATA_START_OFFSET (YDB_TABLE_FILE_SIGN_SIZE + YDB_TABLE_FILE_VER_MAJOR_SIZE + \